1. Field of the Invention
The present invention relates to a workpiece support apparatus and, in particular, to an apparatus which positions the workpiece and provides support while allowing access to both sides of the workpiece.
2. Description of Related Art
Electronic packages such as multilayer ceramic packages can be manufactured using unfired ceramic greensheets which are nominally 0.2 mm or 0.28 mm thick. Typical greensheets which are 185 mm or 215 mm wide are worked to make up to nine parts or electronic packages per sheet.
It is desirable to use larger workpieces, for example, 450 mm wide greensheets could be used to make up to 81 electronic packages per sheet. However, larger greensheets are subject to sagging and stretching which makes them difficult to handle and work. Tooling such as cutting, punching, laser cutting, drilling or the like requires appropriate support. Present methods do not facilitate the working of large workpieces because they do not provide the appropriate support for the workpiece which could cause inaccurate patterning.
Further, conventional methods limit access to at least one side of the workpiece, i.e. the bottom side, and provide a limited active area. The active area of the workpiece is the area subject to the tooling. For example, a 450 mm wide greensheet can have an active area 418 mm wide. Access to all sides of the active area is preferred. For instance, access to the bottom side of a workpiece would allow the positioning of tooling, such as a vacuum plenum, underneath the workpiece and access to the largest possible area would alleviate the problem of void areas which cannot be worked.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a workpiece support apparatus for supporting a workpiece whereby access to an entire active area is possible.
It is another object of the present invention to provide a workpiece support apparatus for supporting a workpiece whereby access to top and bottom workpiece areas is provided.
A further object of the invention is to provide a workpiece support apparatus for supporting a workpiece which minimizes sagging and stretching of the workpiece, particularly at the point of the machining operation.
It is yet another object of the present invention to provide a workpiece support apparatus for supporting large flexible workpieces.
It is yet another object of the present invention to provide a workpiece support apparatus which may be used for positioning the workpiece.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The above and other objects, which will be apparent to those skilled in the art, are achieved by the present invention which in a first aspect relates to a workpiece support apparatus for positioning a workpiece comprising: a holding fixture frame; a means to secure the workpiece to said holding fixture frame; and a support member for supporting the workpiece, said support member being secured to said holding fixture frame for movement with respect to said holding fixture frame; whereby at least a portion of said support member is adapted to contact the workpiece and said holding fixture frame and the workpiece are movable with respect to said support member while said support member contacts the workpiece.
In another aspect, the present invention relates to a workpiece support apparatus for positioning a workpiece comprising: a stationary base; an X-Y positioning system mounted to said base adapted to facilitate movement of the workpiece; a holding fixture frame mounted to said X-Y positioning system, said holding fixture frame having first and second opposing inside edges and an outside surface; a plurality of rollers mounted to said holding fixture frame; a guide rail rolling support assembly comprising first and second spaced guide rails with first and second ends and guide rail rolling supports, said first guide rail rolling support mounted to said first and second guide rails at said first ends, said second guide rail rolling support mounted to said first and second guide rails at said second ends, said guide rail rolling support assembly moves along said holding fixture frame opposing first and second inside edges; a plurality of support wires attached at one end to said first guide rail and at another end to said second guide rail each of said support wires received by aligned grooves in said holding fixture frame outside surface and said rollers; and a plurality of locator pins adapted to hold the workpiece in place on said holding fixture frame.
In another aspect, the present invention relates to a method of positioning a workpiece comprising the steps of: a) providing a workpiece support apparatus for positioning a workpiece comprising: a holding fixture frame; a means to secure the workpiece to said holding fixture frame; a support member for supporting the workpiece, said support member being secured to said holding fixture frame for movement with respect to said holding fixture frame; whereby at least a portion of said support member is adapted to contact the workpiece and said holding fixture frame and workpiece are movable with respect to said support member while said support member contacts the workpiece; b) providing a workpiece; c) placing the workpiece on said workpiece support apparatus support members; d) moving said holding fixture frame with respect to said support member to effect movement of said holding fixture frame and the workpiece; and e) positioning the workpiece in a desired position.
In another aspect, the present invention relates to a method of positioning a workpiece comprising the steps of: a) providing a workpiece support apparatus for positioning a workpiece comprising: a stationary base; an X-Y positioning system mounted to said base adapted to facilitate movement of the workpiece; a holding fixture frame mounted to said X-Y positioning system, said holding fixture frame having first and second opposing inside edges and an outside surface; a plurality of rollers mounted to said holding fixture frame; a guide rail rolling support assembly comprising first and second spaced guide rails with first and second ends and guide rail rolling supports, said first guide rail rolling support mounted to said first and second guide rails at said first ends, said second guide rail rolling support mounted to said first and second guide rails at said second ends, said guide rail rolling support assembly moves along said holding fixture frame opposing first and second inside edges; a plurality of support wires attached at one end to said first guide rail and at another end to said second guide rail each of said support wires received by aligned grooves in said holding fixture frame outside surface and said rollers; and a plurality of locator pins adapted to hold the workpiece in place on said holding fixture frame; b) providing a workpiece; c) placing the workpiece on said workpiece support apparatus support wires; d) moving said X-Y positioning system with respect to said base to effect movement of said holding fixture frame and the workpiece; and e) positioning the workpiece in a desired position.